@article{art:CTS,
    author={P. J. Steinhardt and L. Wang and I. Zlatev},
    title={{\it Cosmological tracking solutions}},
    year={1999},
    journal={Phys. Rev.}
    volume={D59}
    number={123504}
}

@article{art:piccolo,
    author={P. J. Steinhardt and L. Wang and I. Zlatev},
    title={{\it Quintessence, Cosmic Coincidence, and the Cosmological
        Constant}},
    year={1999},
    journal={Phys. Rev. Letter}
    volume={82}
    pages={896--899}
}

@article{art:DEAU,
    author={Joshua A. Frieman and Michael S. Turner and Dragan Huterer},
    title={{\it Dark Energy and the Accelerating Universe}},
    year={2008},
    journal={Ann. Rev. of Astronomy and Astrophysics}
    volume={46}
    pages={385--432}
}

@article{art:exp,
    author={Pedro G. Ferreira and Michael Joyce},
    title={Cosmology with a Primordial Scaling Field},
    year={1998},
}

@book{book:liddle,
    author={Andrew Liddle},
    title={An Introduction to Modern Cosmology},
    year={2003},
    publisher={Wiley}
}

@book{book:coles,
    author={P. Coles and F. Lucchin},
    title={Cosmology: The Origin and Evolution of Cosmic Structures},
    year={2002},
    publisher={Wiley}
}
